RESUMEN
BACKGROUND: Hand-arm vibration (HAV) is a risk factor for carpal tunnel syndrome (CTS) and ulnar neuropathy at the elbow (UNE). It is unclear how ergonomic factors influence the relationship between HAV exposure and CTS and UNE. AIMS: We aimed to assess the relationship between cumulative HAV exposure and CTS and UNE in workers exposed to HAV from two tools with different ergonomic profiles. METHODS: We performed nerve conduction studies (NCSs) of the sensory and motor median and ulnar nerves and recorded symptoms indicating CTS and UNE in workers exposed to HAV from impact wrenches or from rock drills. Exposure was measured as cumulative lifetime exposure. We used linear regression adjusted for age and body mass index to assess linear relationships. RESULTS: Sixty-five workers participated (33 rock drill and 32 impact wrench operators). We found inverse linear associations between cumulative HAV exposure and median nerve sensory conduction velocity in impact wrench operators and ulnar nerve motor conduction velocity in rock drill operators (beta of 0.63 and 0.75). Based on NCS findings and symptoms, seven impact wrench operators had CTS and one UNE, and four rock drill operators had CTS and six UNE. CONCLUSIONS: Our findings indicate that ergonomic factors influence the development of CTS and UNE under HAV exposure. The ergonomic profile seems to influence which type of neuropathy workers exposed to HAV will develop. Design of occupational exposure guidelines and future studies should be based on ergonomic profile and exposure characteristics for different tools and not merely HAV.
Asunto(s)
Síndrome del Túnel Carpiano , Enfermedades del Sistema Nervioso Periférico , Humanos , Vibración/efectos adversos , Conducción Nerviosa/fisiología , Enfermedades del Sistema Nervioso Periférico/etiología , Síndrome del Túnel Carpiano/etiología , Síndrome del Túnel Carpiano/diagnóstico , ErgonomíaRESUMEN
The impact over a 12-month period of a major increase in enrollment of prepaid insurance patients on the clinical, administrative, and educational activities of a university-based family practice residency program is described. Patient services increased by 40 percent, placing a heavy clinical load on faculty and third-year residents. There were significant increases in referral to psychology, psychotherapy, ophthalmology, and otolaryngology specialists. The high demand for services caused logistical difficulties for office and nursing staff. Adaptation to these changes and cost-containment efforts were hampered by institutional relationships. Strategies to manage the impact included hiring additional staff and part-time clinicians, introducing quality assurance and internal control procedures, and repeated orientation to the prepaid plan. Overall, the impact of the plan was of educational value to both residents and faculty.